• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4197-4203
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• 2013

In order to investigate the heating performance of multi-heat pump applying an inverter compressor, the experiment on heat pump with 3 indoor units was performed under the heating standard and heating low-temperature conditions. The performance data of heat pump with 3 indoor units were measured by the multi-psychrometric calorimeter. The operation characteristics and the behavior of the refrigerant cycle of the heat pump with 3 indoor units were understood from the heating capacity, heating COP, and P-h diagram by indoor-unit combination. The present experimental results show that the operating load and performance of the multi-heat pump depends on the indoor-unit combination. The heating capacity and heating COP of the low temperature condition were smaller than those of the standard one. Also the refrigerant cycles on indoor-unit combination were analyzed by using P-h diagram.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1487-1493
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• 2008

In order to investigate the cooling capacity of multi-heat pump applying an inverter compressor, the experiment on the cooling performance characteristics of heat pump with 3 indoor units was performed under the cooling standard and cooling low-temperature conditions. The system data were measured by the psychrometric calorimeter. The operation characteristics and the behavior of the cooling cycle of the heat pump with 3 indoor units were understood from the cooling capacity, COP, and P-h diagram by indoor-unit combination. The operating load and performance of the multi-heat pump depends on the indoor-unit combination. The cooling capacity and COP of the low temperature condition were larger than those of the standard one. Also the cycle was analyzed by using P-h diagram.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.441-448
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• 2000

The production and cation flux-mediated activation of the P-type ATPase in Helicobacter pylori was investigated. Using the polymerase chain reaction (PCR), the proton pump genotype of H. pylori was found to be positive for both F-type and P-type ATPases. Yet, their production in terms of enzyme specific activity varied substantially depending on H. pylori strains, ranging over 3-fold. Its main constituent appeared to be the P-type ATPase pool, in contrast to other common bacterial compositions. Interestingly, the F-type ATPase was observed only when intact H. pyloricells were exposed to pH 4.5 or above (37$^{\circ}C$ for 1 h). In contrast, significant amounts of the P-type ATPase still remained after 1 h of cell treatment even at pH below 4.5. By enriching the acidic medium with RPMI(pH 3.0), the P-type ATPase was stabilized, accompained by inactivation of the F-type ATPase. Using H. pylori membrane vesicles, it was found that ammionia-mediated cation flux increased the rate of ATP hydrolysis by the P-type ATPase. Accordingly, these data strongly suggest that the P-type ATPase is involved or functions as an effective regulator for the cation flux across the H. pylori membrane, thereby reducing the risk of excess proton influx.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.473-474
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.737-738
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.741-742
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• 2007

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.577-583
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• 2018

Background/Aims Potassium-competitive acid blockers are expected to be the next generation of drugs for the treatment of diseases caused by gastric acid. In 2015, vonoprazan fumarate, a novel potassium-competitive acid blocker, was approved by the Japanese health insurance system. Since its approval, patients refractory to vonoprazan can be encountered in clinical settings. We designed this study to clarify the pathophysiology of gastroesophageal reflux disease refractory to vonoprazan. Methods In this retrospective study, we involved patients who had refractory symptoms after administration of standard-dose proton pump inhibitors or vonoprazan and underwent diagnostic testing with esophageal high-resolution manometry and 24-hour multichannel intraluminal impedance and pH monitoring while using proton pump inhibitors or vonoprazan. Patients were diagnosed based on the Rome IV criteria for functional gastrointestinal disorders and diagnostic test results. Results Twenty-seven patients were analyzed during this study. Gastric pH ${\geq}4$ was sustained for a longer period of time, and the esophageal acid exposure time and number of acid reflux events were shorter in the vonoprazan group than in the proton pump inhibitor group. The percentage of patients diagnosed with acidic gastroesophageal reflux disease in the vonoprazan group was lower than that in the proton pump inhibitor group. Conclusions Intra-gastric pH and acid reflux were strongly suppressed by 20-mg vonoprazan. When patients with gastroesophageal reflux disease present symptoms after administration of 20-mg vonoprazan, the possibility of pathophysiologies other than acid reflux should be considered.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.95-96
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• 2009

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.13-16
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• 2004

Deep sea water has mid temperature, abundant nutrients and minerals, and good tooter quality. For the purpose of drawing up deep sea water without pump pit construction, tile authors are considering to use air-lift pump. This report describes fundamental experimental investigation for air-lift pump characteristic and improvement in efficiency.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.247-251
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• 2008

This paper presents a micro air pump actuated by PZT actuator (synthetic jet actuator) for air supply for micro fuel cells. The synthetic jet actuators are usually created by a traditional PZT-driven actuator, which consists of a small cylindrical cavity, in/outlet channel and PZT diaphragms. To design the micro air pump, a numerical analysis has been conducted for flow characteristics with respect to various geometries. A prototype of the micro air pump, with a size of $mm{\times}mm{\times}mm$, was fabricated by PDMS replication process and was conducted performance test. To control the PZT actuator, we used the SP4423 micro chips that can be amplified input voltage to reduce the controller size and the power consumption. With a voltage of 3V at 100Hz, the air pump's pumping pressure is 600pa and its power consumption is only 0.1mW.